A fun way to watch this movie, if of a Buddhist slant, other reincarnation religion, is to see our dashing Fitzgerald as Aguirre reincarnated.
True to karmic form, he's learned a thing or two in the afterlife. For example, he's now much better with women (which isn't saying a whole lot, given where we were in Part One).
Herzog provides this outrageous director's commentary, providing this back story about how the movie had to restart when Jason Robards and/or Jack Nicholson fell ill and/or thought life was too short, and Mick Jagger (Herqueque?), though willing to forego many pleasures, had gigs to get back to.
So it was back to Klaus Kinski, always Werner's top choice, but too inclined to freak out in the Peruvian Jungle (witness Aguirre).
That scene with Fitzgerald going absolutely bats in the belfry, wanting his opera house, rivals the best of Jim Carrey, with or without a mask. And he gets one in the mix, dreams do come true, which is the happy ending... and that this movie got made, yay.